Improved metallic door or shutter



v ttuitrd ltere @will @titille ALFRED B.MULLETT AND BARTHOLQMEW OERTLY,0F WASH? moron-,DISTRICT or COLUMBIA.

Letters Patent No. 92,205, dated July 6, 1869; antedated .Tune 30, 1869.

IMPROIEID METALLIC DOOR OR SHUTTER.

The Schedule referred to i'n theae'Lettexs Patent and making'paxt o'flthe neme.

10 all whom ,llt Ina/y concern Be it known that we, ALFRED B. MULLETT'and BARTHOLOMEW OERTLY, both of the city of Wash the following isasufliciently full, clear, and exact description' thereof to enable oneskilled in the art to which our said invent-ion appertains, to make andcarry it into effect, reference being had to the accompanying drawings,which are made a part of this specification.

Our invention consists in an 'improved manner of constructing fire'proofmetallic doors and'shutters, by framing and bracing them together insuch a manner as to dispense with Welding the frame, and thereby reducethe cost of manufacture, and facilitatethe introduction of tire-proofmaterial.

In the drawingst.

Figure 1 is a front'view of one of our improved doors or shutters,certain parts being removed, in order to expose parts in rear thereof,as hereinafter explained. .Figure 2 represents a longitudinal sectionjat x x,

Figure 3 represents, on a larger scale, a partial sec-` tion in the sameplane as fig. 2.

'Figure 4 is a longitudinal sectional view of the edge frameshereinafter described.

Similar letters of referencej indicate corresponding parts in all thefigures.

A A representmetallic sheets, secured at their edges to straight rigidbars B B', by means gf rivets or bolts u. a, which may extend completelythrough from one face to the other of the shutter.

Crossed diagonal braces, D,' are employed to afford additional strengthand rigidity to the structure.

To afford convenient means of securing'the ends of lthese braces theedge flames B B' may be made each in three parts, the central one, B',of which being of greater width than the vothers, projects between theends of the braces which are riveted to it, leaving their faces Hushwith the frame,'and permitting the shee metal to be placed evenly overthe whole.,

' O represents a body of plaster of Paris, or other nonconductor of vheat,pwhich is poured in through an open end of the door or shutter, whileone end piece ofthe frame B is 'ou t.

In iig. 1, the upper part ofthe frontmetallic sheet A is omitted, toexpose the braces D and lire-proof filling, andportions of the tireprooffilling O are also omitted, showing the rear brace and sheet-metal shellor casing A.

' -Where the parts to be rivetedtogether do not come A in contact,metallic tubes or washers are inserted, as shown at ll in lin'. 1, and din tig. 2, so 4as to afford a firm andlrigid bearing.

If preferred, the edges of the door or shutter may be formed by bendingeither the front or the'rear shell over and around the rigid frames.

We produce, ata less cost than the usual sheet-iron shutter, riveted t0a welded frame, a strictly fire-proof shutter, offering double theresistance to burglars, and are enabled .to-furnish vit as so low aprice as to enable their use onwarehousesor any other buildings, whereprotection' from lire and burglars is essential.

Our divided frame also affords 'greattacility for pouring in thefire-proof material.

Any suitable moulding may be formed upon the bent edges ofthesheetemetal shells.

The necessary rebates may be produced Zby setting the stiles orframe-pieces alittleforwardor back from theedge of the door or shutter:

We claim as new, and desire to secure by Letters Patent- A metallic dooror shutter, made by riveting vor bolting two sheets of metal to rigidbars B and braces D, laid between them without welding, allsubstantially as and for the purposes herein specified.

- A. B. MULLETT.

Witnesses: B. OERTLY.

GnaG. LYON, GORDON MAcLnoD.

